Tread grip



' I 16,680 1 July 19, 19.27. c. L. HOFF Re TBEAD GRIP.

' Original Filed April 21. 1923 a 2'- ZIMQIZ/df aarzz'on L .Haf

Alior'ney celes prism.

Reiaued July 19, 1921.

UNITED STATES.

I R lease PATENT OFF-ICE.-

OAIUI'ON' L. H", OI' YORK, PENNSYLVANIA; ASSIGKOB '10 E01! man PRODUCE! comm, OF NEW YORK, N. 1.,

A COBPORATIOH Ol' nmwm" 'ramm em.

onus-1 Io. 1,409,310, ama m 1, as, mm m. seam, me was, less. Application reissue fled larch 10,

and has for its .princi a1 object the provision of a tread flgn w ich will have longer life, be more e ectlve and of less cost, than devices now available.

An important factor of the resent invention lies in the provision o a rotatably mounted tread member surrounding the cross bar of the tread grip to relieve the cross bar of a tportion of the wear that would otherwise besborne by this member and at the same time form an efiective'traetion increasing and anti-skid member between the tire and roadway.

It is not.new at the present time to provide a tread grip employing a cross bar provided with a rotary member usually a sleeve but as far as I am aware no angular-sleeve has been provided on a cross member of an anti-skid device which would permit the sleeve to turn on its support when the sleeve is away from the ground but which is held against rotation when performing its operative function in contact with the road, this useful efiect being obtained in the present instance by having the sleeve non-circular in cross section and preferably having. the shape of a hollow prism resembling an isosoi chains provided with such isosceles prisms have been tested under very A umber severe conditions and it has been found that the sleeves merely oscillate when in contact a with the ground and tire, presenting freuently a corner to the pavement and a flat side to the tire and at other times presenting a flat side to the ground and a ridge slightly pressed into the tire. As each tread grip passes to the top of the tire as the latter'is rotated the sleeve will be free, since the cross member is not tightly held against'the tire and the sleeve will change its position about its support so as to present difierent edges 7 u or sides to the roadway thus distributing the wear evenly about the prism.

. The cross bar without the sleeve is itself 3 a tread grip member and is an improvement over existing cross bars in that the wear is distributed partly to the center section of i the bar and partly to the two ends which are 19. Serial I0. 14,585.

reversed on themselves to form eyes embracing the usual hooks.

In the drawings,

Figure 1 is a side elevation of a portion of an automobile wheel showin a chain employing my improved tread grip in position on the tire. I V

Fi 2 is avertical section through. the whee .tire, and chain.

F1 8 is preferred'form'of my. tread grip mem r including the she I Flg. 4 1s an end view of the parts shown 1nF1g.3.' I i Fig. 5 is a view ofthe cross bar shown in Fig. 3 but omitting the sleeve, the cross bar itself forming the complete tread grip..

' F1'g. 6 1s a modifi form of tread grip including the reinforcing sleeve.

The anti-skid chain shown in Fig. 1 is similar in appearance to many of the chains now in general use consisting of aplurality of side chains 10 of the usual standard links 11 and carrying a considerable number of transverse or cross members each referably consistin of aspair of hooks 15 o the usual type em racing the eye of my improved cross bar at the center 16 of the hook and embracing a link '11 of one of the chains 10 by its hooked end 17. 4

The s ific 'cross'b'ar of my present invention in its preferred formas shown in Figs. 3 and'5 consists of a single red having a straight central portion 20 continued out to a point near the center of the eyes 21 and then bent upwardly as at 22 and then downwardlyas at 23 to form a closed loop, the end 24 when the loop is finished lying paral- V lel to and, in front of the center port1on20 as seen in Fig. 5 so that the axis of the and 24 will be at the same distance from the axis 'of the wheeland tire as is the axis of the center portion 20 of therod from which the cross bar is made. i As isapparent from Fig. 5 the two ends 24 will contact with the ground, when the device is in use, atthe same time as does'the center portion 20 of the cross bar or link so that the wear will be shared by the center and ends. I find it preferable although'not no at all essential to mount the cross barson the side chains so that the ends 24 will come in contact with the ground before the center 7 portion in other words, I place the ends greater time.

24 so that when they are at-the bottom of the wheel or tire they face toward. the rear of-the vehicle so that the ends of the'cross bar Wear more than the center; ortion of the link, retaining the strength of the center portion of the cross bar for a materially An additional advantage 1n this construction lies in the fact that should the wheel lose traction by spinning the cross bars will tend to'rock thereby presenting an edge, so to speak, to the roadway, In other words the ends 24 will tend to dig into the roadway and so greatly increase the traction of the wheel. V

The cross bar shown in Fig. 3 is remforced by a tread member 30 preferably formed of a substantially rectangular sheet of steel bent twice through an angle of 120 so as to form a hollow prism sleeve having a cross section of the shape of. an isosceles tr1-' angle having a base ,31 and two sides 3.2. The edges of the sheet metal plate from which the sleeve is made are butted together as at 34 to close the prism and form one of the three edges of the sleeve While the edges at 34 are shown sharp in Fig. 4. it has been found that the sleeves in use soon close the joint at 34 and that after one of my sleeve type tread grips has been in use for as much at a hundred miles on hard pavements it is ahnost impossible to find the joint 34 from the outside of the sleeve, the joint at this time having the appearance of a welded seam. I

v The size of the triangular central space inside the hollow sleeve is preferably such as to permit freeangular shifting of the sleeve on the central portion 20 of the cross bar when the sleeve is thrown away from the tire by the centrifugal action of the wheel and the prism is preferably of such length as to fit loosely between the two coaxial ends 24 of the cross bar whereby a sufficient lateral movement of the sleeve is ermitted to prevent any possibility of inding or locking of the parts.

There appears to be no tendency on the part of my sleeves to rotate when in contact with the tire and ground. I do not intend that my side chains 10 shall grip the tire with spring tension, but on the contraryI refer to mount the two side chains 10 1 Fairly loosely so that the anti-skid chain asa whole will creep slowly with respect to the tire.

The modified form of cross bar shown in Fig. 6 is generally. quite similar to the form shown in Figs. 3 and 5 but is somewhat more expensive to make inasmuch as it is necessary to perform two operations, one to 1 bend the end of the. link to form the closed loop or eye as 36. In the modified type, as in the preferred type, the ends here num- ,ably mounted on said bered 37 are made coaxial one with another and parallel to the axis of theocenterportion of the rod.

Having thus described my invention. I claim: v 1. In a device of the class described, the combination with a vehicle wheel, of a flexible'anti-skid device loosely encircling the tread portion of the wheel, said device including a plurality of tread members each having a rotary movement about a contained axis extending transversely of the plane of the wheel and having its periphery definedby a plurality of wheel engaging faces and with adjacent faces an ularly disposed, said member being held rom rotary movement when .inoperative position between the ground and the wheel and, when thrown clear of, the wheel b as it is revolvedbodily by the wheel.

2. In an anti-skid device, means for connecting side members, a tread member rotat{ means and having a plurality of flat sides connected to form acute angle corners and stops for limiting relative axial movement of the tread member on said means whilev permitting complete rotary movement of said tread member.

3. In an anti-skid device, atransverse cross member comprising a bar, a sleeve loosely mounted on the bar, said sleeve consisting of a metal sheet bent twice to an angle of approximately sixty degrees to form'a hollow prism. I

4. In an anti-skid device, the combination of a cross-bar, and a sleeve triangular in gross-section rotatably mounted on said cross 5.-In a device of the class described, the combination of a tread member having a plurality of substantially flat tread surfaces and means for mounting the member to permit rotation about a contained axis thereby to cause the different surfaces to come into operative position. Y

6. In an anti-skid device, a transverse cross bar, a sleeve loosely mounted on said cross bar, said sleeve having apluralit of acute angle corners, and means on eac of said cross bars for limiting lateral movementof said sleeve said cross bar comprising a single rod'bent near its ends to form eyes and with its extremities parallel to the central portion of the bar and at the same distance from the axis of the wheel and tire.

7 In an anti-skid device, a cross bar, a sleeve loosely mounted on said cross bar, and reversely directed ends on said cross bar parallel to the central portion, thereof forming stops to limit endwise movement of sai centrifugal action, be ng free to rotate an then present- -1ts different faces to the wheel including a bar having a central bearing portion, a tread member rotatably mounted on ing its adjacent sides angularly disposed and said portion, the ends of said bar being bent each adapted to contact with the ground or to one side of and back upon the central porwith the wheel on which it is mounted, and 15 tion to'form ofiset stops for limiting the means for rotatably mounting said member 5 axial movement of the tread member. for movement about a contained axis where- 9. In an anti-skid device, a groundengagby the tread member is free to rotate and ing member mounted for rotary movement oscillate and thus vary the presentation of about an axis and outlined by a plurality of its different sides to the wheel and ground. substantially flat surfaces, each tangent to a Signed at New York city, county of New thrown circle about said axis. York {and State of New York, this 28th day 10. An anti-skid device for vehicle wheels, of Feb. 1925.

including a multi-sided tread member hav- CARLTON L. HOFF. 

